Fuel cell feeds on sewage

The Canadian Water Quality Association reports that environmental engineers in the U.S. have developed a prototype microbial fuel cell that can generate electricity while treating wastewater.
Pennsylvania State University and the National Science Foundation did the research, which to date has been conducted on a small scale using wastewater skimmed from a settling pond.
Typical fuel cells run off hydrogen, but in a microbial fuel cell bacteria metabolize their food to release electrons that yield a steady electrical current. In this research, the "food" is organic matter in wastewater.
While the power generated from the sewage in the research is miniscule, the potential of such technology for reducing wastewater treatment plant operating costs is enormous for both the developing and industrialized countries.
CWQA’s April 2004 Communique reports that to date the Penn State University experiments have produced up to 50 milliwatts of power per square metre of electrode surface, or about 5 per cent of the amount needed to run a mini-Christmas tree light. At the same time the process removed up to 78 per cent of organic matter from the water.